Welcome Guest! If you are already a member of the BMW MOA, please log in to the forum in the upper right hand corner of this page. Check "Remember Me?" if you wish to stay logged in.

We hope you enjoy the excellent technical knowledge, event information and discussions that the BMWMOA forum provides.
Why not take the time to join the club, so you can enjoy posting on
the forum, the club magazine, and all of the discounts and benefits the BMWMOA offers?Want to read the MOA monthly magazine for free? Take a 3-month test ride of the magazine; check here for details.

If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You will need to join the MOA before you can post: click this register link to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

NOTE. Some content will be hidden from you. If you want to view all content, you must register for the forum if you are not a member, or if a member, you must be logged in.

1200 battery problems

Just picked up a new leftover '08 K1200S and I'm having an issue with the battery. The dealer tells me that if the bike is left dormant for more than 2 days, it must be hooked up to a tender. Supposedly the computer's draw is enough to drain a fully charged battery in a matter of days. This sounds absurd, since my other BMW's can sit for 2 months with no charger, and still start. Any feedback on this will be appreciated.

Just picked up a new leftover '08 K1200S and I'm having an issue with the battery. The dealer tells me that if the bike is left dormant for more than 2 days, it must be hooked up to a tender. Supposedly the computer's draw is enough to drain a fully charged battery in a matter of days. This sounds absurd, since my other BMW's can sit for 2 months with no charger, and still start. Any feedback on this will be appreciated.

Not true. The drain on the battery should be around 10ma or less. Mostly less. I let them sit (K12S) about 3 to 4 weeks and then put the tender on it. The battery goes to float on about 10 hours or less. Mostly less again.
Note that a battery self discharges faster in the summer (warm) than in the winter.
Your battery is probably hurting. It may have been allowed to go flat by the dealer for prolonged periods of time sitting in the showroom. If the battery is less than 2 years old, and cannot hold a charge, the battery is under full replacement warranty.

I too had similar problems with my brand new 2008 K12GT. The battery would die in about 3 days which was very disconcerting to say the least on a bike that only had 350 miles on it!

My dealer (MAX BMW / N. Hampton, NH) was fabulous. They replaced the battery under warranty with a much better BMW gel-type battery. They did wrench a few extra bucks from my pocket, as I purchased a CAN-BUS compatible battery tender (BMW). The combination has been perfect however. The tender keeps the battery in the green and it starts without hesitation every time since.

Worth the extra dollars to know you don't have to hassle removing cables from the battery so you can put a charger on it! Did that once and that was enough for me.

Battery Drain

I had an R1100RT, K1200RS (and a BMW Z3 Automobile) and they all drained the battery way faster than any other brand vehicle I've ever owned (and I'm pretty old). I just bought a new 08 K1200GT and the first accessory I bought was a charger under the assumption that it too would die quickly. Not sure why, I assumed it was the computer on all three of them.

Battery Charge

Count my lucky stars, so far. My 08 K12S is now one year old, has 15,000 miles and has sat as long as several weeks without running, and has always started without hesitation. Course, now that I have written this...

They replaced the battery under warranty with a much better BMW gel-type battery. They did wrench a few extra bucks from my pocket, as I purchased a CAN-BUS compatible battery tender (BMW).

I was not aware that there is a CAN-BUS compatible battery tender. There is a gel battery compatible battery charger/tender. Gel batteries require a different battery charger than lead acid / AGM type batteries. Using a non gel compatible charger to charge a gel battery will damage the gel battery and decrease its life.

I do not consider a gel battery to be better than a sealed lead acid battery. I consider it inferior. Gel batteries tend to quick working abruptly without much warning and it needs a special battery charger.

I just changed out my 5 year old gel battery for a sealed lead acid battery. It's much cheaper. Better battery.

If they are correct, $160 for a battery charger to charge through an accessory port on a CAN-BUS bike is too expensive. The alternative is to disconnect the battery to charge it. Not much of a choice. I'll stick with the the older, simpler bikes.

I have a 2006 K1200R and it matches the symptoms here in this thread. I charged the battery a little and then 'jumped' it with the charger. I then rode it around for 30 minutes and got gas. Bad idea! The bike didn't have enough juice to start up again.

The result is an action of my choice I guess but now I need to replace the battery. It doesn't look like it will take a charge anymore. Besides going to BMW has anyone replaced their battery with a non-bmw type? If so what type and where did you get it?

While I am at it, is there any evidence that charging the battery at the terminals without disconnecting the power cable causes any harm?

Buy an appropriate charger, charge it every time you park it, and 30 min won't work.

Have a good charger but didn't think I needed it every week. As stated in other posts one would think you could go a few weeks without a charger. My GS doesn't seem to need a charger except in the winter. BTW, both bikes get a charger during winter.

I can let my '06 K12GT sit for 2 weeks and it starts with just a little more starter time than if I ride it every day. (yeh, I know, why do I leave it sit for 2 weeks. Life happens!!) I have the stock battery in it from '06. I do not use a charger during the summer and haven't had a problem.